We report a rational synthesis of carbon nanodots (CNDs) aimed at tailoring their emission, starting from a reasoned choice of organic precursors. To showcase the potential of this approach in a field such as optoelectronics, we designed experiments aimed at preparing materials that emit across the entire visible spectrum. Specifically, using precursors such as arginine, ethylenediamine, naphthalene dianhydride, and 2,6-dibromonaphtalene dianhydride, in appropriate ratios, it was possible to obtain pure white-light (0.33, 0.33; CIE coordinates) emitting carbon nanodots (WCNDs) through a one-step microwave-assisted synthesis and facile purification. The characterization and properties of this novel nanomaterial is discussed.